Refactor NaClProcessHost. Reduce chances to leak the resource.

components/nacl/loader/nacl_listener.cc

Index: components/nacl/loader/nacl_listener.cc
diff --git a/components/nacl/loader/nacl_listener.cc b/components/nacl/loader/nacl_listener.cc
index 4a58a1ce49bcd8a2814fab35a611bdf91ecd2028..56bb8d419911c0743126dc712f4a4a0168f9484f 100644
--- a/components/nacl/loader/nacl_listener.cc
+++ b/components/nacl/loader/nacl_listener.cc
@@ -337,7 +337,7 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
           manifest_service_handle)))
     LOG(ERROR) << "Failed to send IPC channel handle to NaClProcessHost.";
 
-  std::vector<nacl::FileDescriptor> handles = params.handles;
+  std::vector<IPC::PlatformFileForTransit> handles = params.handles;
   struct NaClChromeMainArgs* args = NaClChromeMainArgsCreate();
   if (args == NULL) {
     LOG(ERROR) << "NaClChromeMainArgsCreate() failed";
@@ -348,15 +348,16 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
   args->number_of_cores = number_of_cores_;
   args->create_memory_object_func = CreateMemoryObject;
 # if defined(OS_MACOSX)
-  CHECK(handles.size() >= 1);
-  g_shm_fd = nacl::ToNativeHandle(handles[handles.size() - 1]);
+  CHECK(!handles.empty());
+  g_shm_fd = IPC::PlatformFileForTransitToPlatformFile(handles.back());
   handles.pop_back();
 # endif
 #endif
 
   DCHECK(params.process_type != nacl::kUnknownNaClProcessType);
-  CHECK(handles.size() >= 1);
-  NaClHandle irt_handle = nacl::ToNativeHandle(handles[handles.size() - 1]);
+  CHECK(!handles.empty());
+  NaClHandle irt_handle =
+      IPC::PlatformFileForTransitToPlatformFile(handles.back());
   handles.pop_back();
 
 #if defined(OS_WIN)
@@ -380,7 +381,8 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
   }
 
   CHECK(handles.size() == 1);
-  args->imc_bootstrap_handle = nacl::ToNativeHandle(handles[0]);
+  args->imc_bootstrap_handle =
+      IPC::PlatformFileForTransitToPlatformFile(handles[0]);
   args->enable_debug_stub = params.enable_debug_stub;
 
   // Now configure parts that depend on process type.
@@ -411,8 +413,9 @@ void NaClListener::OnStart(const nacl::NaClStartParams& params) {
   }
 
 #if defined(OS_LINUX) || defined(OS_MACOSX)
-  args->debug_stub_server_bound_socket_fd = nacl::ToNativeHandle(
-      params.debug_stub_server_bound_socket);
+  args->debug_stub_server_bound_socket_fd =
+      IPC::PlatformFileForTransitToPlatformFile(
+          params.debug_stub_server_bound_socket);
 #endif
 #if defined(OS_WIN)
   args->broker_duplicate_handle_func = BrokerDuplicateHandle;